Takeda Pharmaceutical Company Limited announced data from ELM PC4, a pivotal, international, double blind, randomised phase 3 trial showing that the investigational drug orteronel plus prednisone reduced the risk of radiographic progress ion free survival (rPFS), one of the study’s two primary endpoints, by 30 per cent compared to placebo plus prednisone in men with chemotherapy naïve metastatic castration resistant prostate cancer (mCRPC).

The second primary endpoint, overall survival (OS), showed a numerical improvement in median OS of 1.9 months that was not statistically significant [median OS: 31.4 vs. 29.5 months (HR 0.9; 95 per cent CI: 0.8 1.1; P=0.314)]. Results from the study will be presented as an oral presentation on June 1 during the Genitourinary (Prostate) Cancer session at the annual meeting of the American Society of Clinical Oncology (ASCO).

“The significant rPFS advantage observed for orteronel combined with pred nisone in the ELM PC4 study is consistent with the previously reported rPFS improvement observed in the ELM PC5 study, where orteronel was also studied with prednisone in men with mCRPC who had previously received chemotherapy. We are carefully analysing these data to fully inform future decisions in the orteronel programme,” said Michael Vasconcelles, managing director, Global Head, Takeda Oncology Therapeutic Area Unit. “We thank and express our gratitude to the patients, their families and the study investigators for their significant contributions to the orteronel programme date.”

The abstract, titled “phase 3, randomised, placebo controlled trial of orteronel (TAK700) plus prednisone in patients (pts) with chemotherapy naïve metastatic castration resistant prostate cancer (mCRPC) (ELM PC 4trial) [Abstract #5008]”, compared orteronel 400 mg twice daily (BID) plus prednisone 5 mg BID to placebo plus prednisone in 1,560 men with progressive chemotherapy naïve mCRPC (rising PSA and/or radiographic  evidence of metastases) and serum testosterone <50 ng/dL post orchiectomy or with maintained GnRH suppression. In the study, men with progressive mCRPC were randomised 1:1 to either treatment or control groups.

The final analysis for rPFS was conducted at an interim analysis for OS, and the final analysis for OS was conducted at 600 deaths. The results will be presented by Ronald DeWit, managing director, Erasmus MC Cancer Institute. Key secondary endpoint showed more patients experienced at least a 50 per cent decrease in prostate -specific antigen and favourable circulating tumour cell (CTC) counts at 12 weeks in the treatment arm compared to the control Common all (36 per cent s. 15 per cent), fatigue (34 per cent 20 per cent ) constipation (33 per cent vs. 15 per cent ) and diarrhoea  (28 per cent )vs.14 per cent) 30 per cent vs. 18 per cent of patients in the orteronel arm and control arm, respectively,discontinued due to adverse events. No new safety signals attributed to orteronel were identified in this study.